Five years ago this month, Pope Francis became the 266th pope of the Roman Catholic Church and the leader of its 1.29 billion adherents.

He's been celebrating the occasion by reminiscing about his various — and at times controversial — accomplishments since his papal election in March 2013.

The pope has lived these past five years within the walls of Vatican City, the seat of the worldwide Catholic administration, the Holy See, which is nestled on the the west bank of the Tiber River in Rome, Italy.

It is a place that evokes reverence, spiritual power, and a history that spans thousands of years.

Here's a look inside the walls of the beautiful microstate that the world's most powerful religious leader calls home:

Surrounded entirely by the city of Rome, Vatican City is the smallest state in the world, comprising only about 100 acres.

But within its walls sit some of the most famous religious and cultural sites in the world.

Encircling the tiny enclave almost entirely are the imposing Vatican Walls, which were completed in 852 AD.

Usually the first thing visitors see when they pass through these walls is the enormous St. Peter's Square. It's surrounded by Roman columns and features a large obelisk in the center, which Roman Emperor Caligula brought from Egypt.

St. Peter's Square is also where believers gather to hear the Pope speak and deliver sermons from his balcony.

Sometimes, Pope Francis can be caught walking on the square. After all, he does pride himself on being a man of the people.

The centerpiece of the entire Vatican is arguably St. Peter's Basilica, which towers over the square. It took a total of 120 years to complete the building that stands today and its elaborate interior.

Source: Catholic Encyclopedia

Built on Vatican Hill where Roman Emperor Nero is said to have executed St. Peter, the basilica is an ornate and awe-inspiring monument, with works from world-renowned painters and sculptors throughout.

Included among the gardens' natural environs are numerous buildings like Governorate Palace. Today, the papal heliport sits at the far end of the gardens.

There is even a traditional Latin inscription above the heliport that reads: "So that he might thereby more conveniently and comfortably look down from means of travel in Vatican City, Paul VI, Supreme Pontiff."

North of the Basilica and adjacent to the gardens sit the Vatican Palaces — a network of connected buildings that consists of over 1,000 rooms.

The palaces are filled with chapels, government buildings, and apartments, and Popes have called the complex home since the late 14th Century.

The winding museums are a stunning 9 miles long. Some say that if you spent exactly one minute looking at every single piece in the museums, it would take you four years to work your way through them.

The galleries in the museums are spread across ceilings, porticos, walls, and columns.

The crown jewel of the museums is the Sistine Chapel, which houses some of Michelangelo's greatest works. He and several other Renaissance artists worked for over 60 years after the chapel was built to perfect their pieces.

Recruits for the guard must be unmarried Swiss, Catholic men between the ages of 19 and 30. Their uniforms have remained largely unchanged since 1506.

But the Vatican Palaces have not always been safe for the Pope — on a few occasions Popes have fled the Vatican along a passageway called the Passetto di Borgo, which links the palaces to the Castelo Sant'Angelo along the banks of the Tiber River.